Think carefully about the procedure below.
This procedure looks at the technique called recursion and can be used to build up a particularly pleasing catalogue of patterns that spiral!

Investigate this intriguing procedure, try to formulate some ideas about what is happening and test any conjectures that arise.
TO BLOB :A :C
FD 5 RT :A
WAIT 10
BLOB :A + :C :C
END

You will have to tell LOGO to "HALT" at some point otherwise this will go on forever - why?
Try: BLOB 3 9 / BLOB 2 8 and go from there.

BLOB 1 10 and BLOB 11 18 are reproduced here for you...